Because they understand what “variation” means. Granted, the pitch has slowed and become more irregular with its bounce, but just look at what they can do:
1. They bowl faster. Zaheer rarely goes close to 135, but Brett Lee and Mitchell Johnson regularly touch 145.
2. They know how to change their styles: I just saw Johnson bowl a slower ball, a bouncer, a very fast one, all in one over. They also know how to “seam” the ball, that is, get it to vary its line ever so slightly off the pitch.
3. Pressure. Unlike Zaheer, who can be very erratic at times (as he was yesterday), the Australians are experts at simply ratcheting the stakes. They take two wickets; they field much better and stifle the singles; they bowl with wickets in mind, always pushing the opposing team back, back, and back.
In other words, I’m scared. Really scared.